C-5 selective chlorination of 8-aminoquinoline amides using dichloromethane

Abstract

An oxidant-free electrochemical regioselective chlorination of 8-aminoquinoline amides under ambient temperature in batch and continuous-flow was achieved. Inert DCM was used as the chlorinating reagent. Attributing to the continuous-flow setup,...

Paired electrochemical C–H bromination of (hetero)arenes with 2-bromoethan-1-ol

“…The reported paired electrochemical halogenation reactions also use excessive halogen sources. 12,14 Finally, the electrophilic addition of 1 with Br 2 afforded brominated product 3 . The good compatibility and high site-selectivity of the C–H bromination may be due to sustained and low concentrations of Br 2 .…”

Electrochemical Difunctionalization of Alkenes towards the Synthesis of β-Bromoethers under Metal-Free Conditions

“…As outlined in Figure 1 , cyclic voltammetry (CV) of 1,1-diphenylethylene substrate ( 1 ) (curve b) showed an oxidation peak at 2.48 V (vs. Ag/AgCl), which was higher than that of CH 2 Br 2 at 1.93 V (vs. Ag/AgCl) (curve c), so the comparison demonstrated that CH 2 Br 2 could be oxidized more easily than alkene substrate in this galvanostatic mode. It is reported that halogen anion X – and + CH 2 X cation could be generated via C–X bond cleavage of the CH 2 X 2 , 40 thus the involvement of free radical intermediate probably corresponded to the oxidation of Br – to Br • intermediate in curve c (1.93 V) for this electrolysis process.…”

“…Basing on preliminary mechanistic studies and literature reports, 27,[37][38]41 a plausible mechanism was proposed in Scheme 2. Initially, bromine anion Brand + CH2Br cation was gradually generated via C-X bond cleavage of the CH2Br2, 40 In summary, a protocol for electrochemical vicinal difunctionalization of various alkenes was well established in an undivided cell, which employed simple CH2Br2 and alcohol as bromine and alkoxy source without transition-metal mediator or exogenous oxidant. Therefore, it's a green and economical method to synthesize value-added β-bromoethers from cheap starting materials.…”

“…Based on preliminary mechanistic studies and literature reports, 27 37 38 41 a plausible mechanism is proposed in Scheme 4 . Initially, bromine anion Br – and + CH 2 Br cation is gradually generated via C–X bond cleavage of the CH 2 Br 2 , 40 anodic oxidation of bromine anion Br – leads to the formation of bromine radical Br • intermediate, which undergoes radical addition process with alkene substrate I to afford carbon-centered radical intermediate II . After that, nucleophile attack of carbocation intermediate III from anodic oxidation of the resulting intermediate II by alcohol solvent gives the alkyl oxonium salt intermediate IV , which finally delivers the target product through deprotonation.…”

Metal-Free C–C Cross Coupling: Electrosynthesis of Azaheterocycles through Anodic Oxidation Cyclization of 1,6-Enynes

“…In this context, some electrochemical constructions of new C–N, C–O, C–S and C–Cl bonds were reported by us via a radical process. Lei reported an intramolecular oxidative annulation into substituted indoles (Scheme b-1).…”